package com.example.thread;

import lombok.extern.slf4j.Slf4j;
import sun.rmi.runtime.Log;

import java.text.SimpleDateFormat;
import java.util.Random;
/**
 * @author: ZL
 * @Date: 2020/6/9 10:50
 * @Description:
 */
@Slf4j
public class ThreadLocalExample implements Runnable {
    // SimpleDateFormat 不是线程安全的，所以每个线程都要有自己独立的副本
    private static final ThreadLocal<SimpleDateFormat> formatter = ThreadLocal.withInitial(() -> new SimpleDateFormat("yyyyMMdd HHmm"));

    public static void main(String[] args) throws InterruptedException{
//        ThreadLocalExample obj = new ThreadLocalExample();
//        for (int i = 0; i <10; i++) {
//            Thread t = new Thread(obj, "" + i);
//            Thread.sleep(new Random().nextInt(1000));
//            t.start();
//        }
        test();
    }


    @Override
    public void run() {
        System.out.println("Thread Name= "+Thread.currentThread().getName()+" default Formatter = "+formatter.get().toPattern());
        try {
            Thread.sleep(new Random().nextInt(1000));
        }catch (InterruptedException e){
            e.printStackTrace();
        }
        //formatter pattern is changed here by thread, but it won't reflect to other threads
        formatter.set(new SimpleDateFormat());

        System.out.println("Thread Name= "+Thread.currentThread().getName()+" formatter = "+formatter.get().toPattern());
    }

    private static void test() {
        final ThreadLocal threadLocal = new InheritableThreadLocal();
        threadLocal.set("帅得一匹");
        Thread t = new Thread() {
            @Override
            public void run() {
                super.run();
                log.info( "张三帅么 =" + threadLocal.get());
            }
        };
        t.start();
    }
}